Yeah, I know. I have Xp and 6.0 without patch or SP1 too and it works but....I made few test on my servers with IE 5.x->6.0 and....surprise...all of them, 100%, have patch.
Ayone can try that , exploit is great but is so hard to find real targets with that.
Why....answer is simple because of M$blaster, now all W have autoupdate "on" so
if your tagret have DSL or other direct connection on net...
Sorry for my poor lng., anyway I think you can understand most important thing.
BTW. xml exploit was found looong time ago by Grey-Magic, long time ago mean on 27-Feb-2002. The new exploit is just a review of it....check link with more info:
http://sec.greymagic.com/adv/gm001-ie/